On the impact of gap‐filling algorithms on variability patterns of reconstructed oceanic surface fields

The variability and consistency of oceanic surface fields (SST, pressure, air‐sea fluxes) from different sources are studied. The sources are reconstructions using available observations and the NCEP‐NCAR and ECMWF reanalysis. It is shown that the variabilities of different reconstructions differ widely from each other and from those of the reanalyses. Some reconstructed fields are shown to lack internal consistency. It is concluded that variability patterns inferred from gappy data have to be used with great caution. EOF‐based methods are found to yield more reliable results than those based on the method of successive correction.